Belonging to "∈" is a mathematical symbol that expresses the relationship between elements and sets in mathematics. If a∈A, then A belongs to set A, and A is an element in set A. Correspondingly, if A is not an element in set A, it should be written as A? A means that a does not belong to set a.
Extended data:
Mathematical "∈" input method:
1. With sogou input method, open special symbols to select mathematical symbols, and click "∈" to enter; Either enter the word "belonging" in this input method to display the "∑" symbol option, or enter "Yu Shu" in this input method and press 5.
2. Using the intelligent ABC input method, select the "∈" symbol (mathematical symbol) on the soft keyboard.
3. Pinyin with QQ, enter symbols, and there will be "Display more symbols with semicolon-expression" in "Mathematical Unit".
4. Input symbols with universal Wu Bi or Ziguang Pinyin, and open the soft keyboard to input symbols.
5. Use the polar five-stroke input method, enter zzsx and select 9 to display the ∈ symbol.